...
A: closing thread $self{x2}=558
    A=558 B=766 C=970
B: closing thread $self{x2}=766
    A=558 B=766 C=970
C: closing thread $self{x2}=970
    A=558 B=766 C=970
    A=558 B=766 C=970
    A=558 B=766 C=970
    A=558 B=766 C=970